android.media.AudioTrack#getState ( )源码实例Demo

private AudioTrack createStreamingAudioTrack() {
    final int channelConfig = getChannelConfig(mChannelCount);

    int minBufferSizeInBytes
            = AudioTrack.getMinBufferSize(mSampleRateInHz, channelConfig, mAudioFormat);
    int bufferSizeInBytes = Math.max(MIN_AUDIO_BUFFER_SIZE, minBufferSizeInBytes);

    AudioFormat audioFormat = (new AudioFormat.Builder())
            .setChannelMask(channelConfig)
            .setEncoding(mAudioFormat)
            .setSampleRate(mSampleRateInHz).build();
    AudioTrack audioTrack = new AudioTrack(mAudioParams.mAudioAttributes,
            audioFormat, bufferSizeInBytes, AudioTrack.MODE_STREAM,
            mAudioParams.mSessionId);

    if (audioTrack.getState() != AudioTrack.STATE_INITIALIZED) {
        Log.w(TAG, "Unable to create audio track.");
        audioTrack.release();
        return null;
    }

    mAudioBufferSize = bufferSizeInBytes;

    setupVolume(audioTrack, mAudioParams.mVolume, mAudioParams.mPan);
    return audioTrack;
}
 

public boolean startPlayer(int streamType, int sampleRateInHz, int channelConfig, int audioFormat) {
    
    if (mIsPlayStarted) {
        Log.e(TAG, "Player already started !");
        return false;
    }
    
    mMinBufferSize = AudioTrack.getMinBufferSize(sampleRateInHz,channelConfig,audioFormat);
    if (mMinBufferSize == AudioTrack.ERROR_BAD_VALUE) {
        Log.e(TAG, "Invalid parameter !");
        return false;
    }
    Log.d(TAG , "getMinBufferSize = "+mMinBufferSize+" bytes !");
    
    mAudioTrack = new AudioTrack(streamType,sampleRateInHz,channelConfig,audioFormat,mMinBufferSize,DEFAULT_PLAY_MODE);
    if (mAudioTrack.getState() == AudioTrack.STATE_UNINITIALIZED) {
        Log.e(TAG, "AudioTrack initialize fail !");
        return false;
    }            
    
    mIsPlayStarted = true;
    
    Log.d(TAG, "Start audio player success !");
    
    return true;
}
 

public boolean startPlayer(int streamType, int sampleRateInHz, int channelConfig, int audioFormat) {
    
    if (mIsPlayStarted) {
        Log.e(TAG, "Player already started !");
        return false;
    }
    
    mMinBufferSize = AudioTrack.getMinBufferSize(sampleRateInHz,channelConfig,audioFormat);
    if (mMinBufferSize == AudioTrack.ERROR_BAD_VALUE) {
        Log.e(TAG, "Invalid parameter !");
        return false;
    }
    Log.d(TAG , "getMinBufferSize = "+mMinBufferSize+" bytes !");
    
    mAudioTrack = new AudioTrack(streamType,sampleRateInHz,channelConfig,audioFormat,mMinBufferSize,DEFAULT_PLAY_MODE);
    if (mAudioTrack.getState() == AudioTrack.STATE_UNINITIALIZED) {
        Log.e(TAG, "AudioTrack initialize fail !");
        return false;
    }            
    
    mIsPlayStarted = true;
    
    Log.d(TAG, "Start audio player success !");
    
    return true;
}
 

public boolean setPlayer(int rate)
{
    int bufferSizePlayer = AudioTrack.getMinBufferSize(rate, AudioFormat.CHANNEL_OUT_MONO, audioFormat);
    Log.d("====buffer Size player ", String.valueOf(bufferSizePlayer));

    player= new AudioTrack(AudioManager.STREAM_MUSIC, rate, AudioFormat.CHANNEL_OUT_MONO, audioFormat, bufferSizePlayer, AudioTrack.MODE_STREAM);


    if (player.getState() == AudioTrack.STATE_INITIALIZED)
    {

        return true;
    }
    else
    {
        return false;
    }

}
 

/**
 * Initializes or reinitializes the audio track with the supplied format for playback
 * while keeping the playstate. Keeps the current configuration and skips reinitialization
 * if the new format is the same as the current format.
 */
public void init(MediaFormat format) {
    Log.d(TAG, "init");

    boolean playing = false;

    if(isInitialized()) {
        if(!checkIfReinitializationRequired(format)) {
            // Set new format that equals the old one (in case we compare references somewhere)
            mAudioFormat = format;
            return;
        }

        playing = isPlaying();
        pause();
        stopAndRelease(false);
    } else {
        // deferred creation of the audio thread until its first use
        mAudioThread = new AudioThread();
        mAudioThread.setPaused(true);
        mAudioThread.start();
    }

    mAudioFormat = format;

    int channelCount = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
    int bytesPerSample = 2;
    mFrameSize = bytesPerSample * channelCount;
    mSampleRate = format.getInteger(MediaFormat.KEY_SAMPLE_RATE);

    int channelConfig = AudioFormat.CHANNEL_OUT_DEFAULT;
    switch(channelCount) {
        case 1:
            channelConfig = AudioFormat.CHANNEL_OUT_MONO;
            break;
        case 2:
            channelConfig = AudioFormat.CHANNEL_OUT_STEREO;
            break;
        case 4:
            channelConfig = AudioFormat.CHANNEL_OUT_QUAD;
            break;
        case 6:
            channelConfig = AudioFormat.CHANNEL_OUT_5POINT1;
            break;
        case 8:
            channelConfig = AudioFormat.CHANNEL_OUT_7POINT1;
    }

    mPlaybackBufferSize = mFrameChunkSize * channelCount;

    mAudioTrack = new AudioTrack(
            mAudioStreamType,
            mSampleRate,
            channelConfig,
            AudioFormat.ENCODING_PCM_16BIT,
            mPlaybackBufferSize, // at least twice the size to enable double buffering (according to docs)
            AudioTrack.MODE_STREAM, mAudioSessionId);

    if(mAudioTrack.getState() != AudioTrack.STATE_INITIALIZED) {
        stopAndRelease();
        throw new IllegalStateException("audio track init failed");
    }

    mAudioSessionId = mAudioTrack.getAudioSessionId();
    mAudioStreamType = mAudioTrack.getStreamType();
    setStereoVolume(mVolumeLeft, mVolumeRight);
    mPresentationTimeOffsetUs = PTS_NOT_SET;

    if(playing) {
        play();
    }
}